1 Nov 2022
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United Kingdom

I have a Vaillant Ecotec Exclusive with Green IQ 835, VRC700, weather composition, VR920, Ambisense VR50 and V51. I followed the advice of different posts, especially

However, I still have several problems:
  1. In the VRC700 app, two zones are shown, despite having only one, plus a non-existing ventilation system. All zones have ventilation have some weird time schedule, which is not possible to change.
  2. (Only!) During the night the boiler cycles, hot water comfort mode is off. The VRC700f switches to day mode requesting 21C, despite no room requiring heat at this time,

So far I tried the following:
  • Reset the VRC700f
  • Reseted all Ambisense heads and VR51
  • Changed setting of room temp modulation
  • Connected a homeassistant hub with multimatic plugin to a have a history of all temperature and heating request. I use the homeassisstant exclusively for monitoring and connecting it has not changed the behaviour. No heating request is shown during the cycling at night.
The whole thing is quite frustrating. I am a physicist and deal daily with much more complex systems, this system is making a fool out of me.

My aim
I don’t mind having the non-existing zone(s) in the app, as long as they are not causing the problems. But I like to have the boiler not firing when the Ambisense does not request heat, during the set back periode at the night.

My system and settings in detail:
  • One heating circuit, flow and return for each rad
  • 9 rads in total, 7 with Ambisense, 2 with standard TRV on lower setting, hence these two are mostly off
  • 4 of the 7 Ambisense equipped rads joints with a VR51 in the living room
  • Location of the VRC700f currently living room
  • Water pressure is about 1.3bar
  • No cylinder, only DHW

Settings on the VRC700f
Adaptive curve = Yes.
Configure heat circ = Zone 1 (Change to all does not help)
System diagram = 1
Type of circuit = Heating
Max limit outside temp = 17
Heating curve = 1.
Min temp = 25C
Max temp = 60C
Auto off mode = Eco
Room temp modulation = None
Zone 1 activated = yes
Day temp heating = 20.5C
Set-back temp heat = 15C
Zone 1 assignment = VRC700 (I changed this to none, makes no difference)
Cylinder = Inactive
HW temp to 60C.
Ch pump overrun time = 60 min

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